This invention relates to a method and apparatus for applying an elastic waistband to a disposable diaper and, more particularly, to a unique method and apparatus for stretching the waistband in manufacture so as to develop the necessary gathering in the final product.
Illustrative of the prior art for making a diaper product with an elastic waistband is co-owned U.S. Pat. No. 4,523,969. This embodied complicated grippers to provide the stretching of the elastic material. In contrast to that, the instant invention provides a very simple method and apparatus for stretching the elastic material for application to one of the continuous diaper component webs--usually the non-woven web. Disposable diapers historically have included the moisture-pervious (non-woven) for positioning adjacent the body of the infant, an absorbent batt, and an outer web of moisture-impervious material, normally polyethylene.
According to the instant invention, a pair of canted wheels equipped with generally radially extending pins on the peripheries are employed to receive the elastic material at a first position and to deposit the stretched material onto one of the webs at a second position wherein the wheel peripheries are farther apart than at the first position. Thus, rotation of the wheels automatically stretches the web in a simple, uncomplicated manner and which is adapted for high speed, rotary operation.
Pins for mounting webs in converting are well known as seen in co-owned Patent 3,179,348. However, there is no showing that the pins move relative to each other for stretching a web therebetween.